The present invention relates to ion implantation equipment used for semiconductor manufacturing processes, and more particularly, to an ion source section of ion implantation equipment for ionizing impurities used in an ion implantation process during semiconductor manufacturing processes to implant the ionized impurities into a substrate.
As well known, the ion implantation equipment is utilized for generating ion plasma in an arc chamber and extracting the plasma from the arc chamber by the difference in electrical potential energies to implant the extracted plasma into a wafer.
The ion implantation equipment provides a wide beam (or referred to as a ribbon beam) larger than the size of a wafer, e.g., 300 mm, generated in a horizontal direction. A wafer is scanned in a vertical direction to uniformly implant ions into the wafer.
Beam uniformity is very important and the slit of a plate of the arc chamber has the greatest influence on the beam uniformity. An ion beam is generated and initially discharged through the slit of the plate in the form of a beam line. The shape of the slit determines a beam profile.
However, since the slit of the plate is physically shocked by the ion beam and can easily deteriorate, the slit of the plate does not maintain its initial shape. The ion beam deforms to a shape corresponding to the deteriorated slit. Thus, with a deformed slit it is not possible to obtain desired beam uniformity.
In particular, the thickness of the slit of the plate is typically only 0.15 mm and can be easily deformed.
Therefore, to obtain excellent beam uniformity the plate must be periodically exchanged before the slit is excessively deformed. However, since the plate is formed of tungsten, having a high manufacturing cost, the frequent exchange of the plate undesirably increases maintenance and repair expenses.